Does a data plan only apply if you're using the Web via the mobile operator?
The carrier does not supply the internet, as this is an ISP not a mobile telephony operator. So how then would a data plan to the mobile operator apply?
I'm asking since I use my home wifi on my phone, and this is not run by my mobile carrier.
Having a smartphone without a dataplan is like buying a car without wheels.
If you're not gonna have a data plan you don't need a smartphone.